This invention relates to a laminate cutting apparatus in which a number of layers of sheet material such as cloth are cut by a knife-shaped cutting blade.
As disclosed in the specification of Japanese Utility Model Publication No. 55-23836, a conventional laminate cutting apparatus includes a cutter head arranged to move in mutually perpendicular X and Y directions above a support member such as a brush table, and a slender, knife-shaped cutting blade, which has a sharp distal end, mounted on the cutter head so as to be capable of being raised and lowered and turned about a vertical axis.
In operation, the cutting blade of the cutting apparatus is lowered and the cutter head is moved horizontally in the X and Y directions usually from the edge of the laminate placed on the support member, thereby transporting the cutting blade. Concurrently, the cutting blade is turned about the vertical axis so as to point the blade edge in the direction of movement. As a result, the laminate is cut into a desired shape over the entirety of its thickness. There are situations in which it is necessary to cut a laminate starting not from the edge thereof but from above by penetrating the laminate on the support surface from its upper side.
With the conventional laminate cutting apparatus of the type described above, the distal end of the cutting blade can experience elastic deformation if the laminate is thick. This can make accurate cutting impossible and there is the danger that the cutting blade will break. Consequently, there is a limitation upon the thickness of the laminate that can be cut at one time. In an attempt to devise an improvement, a cutting apparatus has been developed in which a blade rest that moves beneath the laminate in synchronization with the cutter head mounting the cutting blade is mounted on the laminate support member. However, the cutting blade must be controlled for accurate forward movement with respect to a cutting line while the blade is penetrating the laminate. To this end, it is necessary that the resistance between the laminate and the cutting blade be reduced to make possible the cutting of curves and sharp corners. Ideally, the cutting blade should be made as small as possible in thickness and in terms of width in the direction of travel. However, with a cutting blade of this kind, elastic deformation thereof often makes it impossible for the blade to vertically penetrate the laminate and have its lower end portion received and retained by a blade receiving body of the aforementioned cutter rest. If the laminate is a material such as chemical fiber or PVC leather, the cut made can be fused by the friction between a cutting blade 10 and laminate 48, as shown in FIG. 11, because almost the entire side face of the cutting blade 10 contacts the laminate 48.
As shown in FIG. 12, the friction between the cutting blade 10 and the laminate 48 can be reduced by cutting the laminate 48 using a cutting member 11 comprising the cutting blade 10 and a cutting blade guide 16. However, when the cutting blade guide 16 is provided, there is too much resistance when it is attempted to vertically penetrate the laminate 48 at the start of cutting, thus making such penetration impossible.